{"id":5083,"date":"2016-09-02T08:00:15","date_gmt":"2016-09-02T14:00:15","guid":{"rendered":"https:\/\/www.ulprospector.com\/knowledge\/?p=5083"},"modified":"2017-06-08T15:02:24","modified_gmt":"2017-06-08T21:02:24","slug":"pcc-vitamin-c-an-effective-skin-care-active","status":"publish","type":"post","link":"https:\/\/ulprospector.ul.com\/5083\/pcc-vitamin-c-an-effective-skin-care-active\/","title":{"rendered":"Vitamin C: An Effective Skin-Care Active"},"content":{"rendered":"

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Vitamin C<\/a>, or ascorbic acid<\/a>, has a long history of topical use and is one of the most researched active ingredients used in skin care. Vitamin C is the major water-soluble antioxidant found in the body and a cofactor in at least eight important enzymatic reactions. As an antioxidant, it destroys free radicals and plays a major role in hydroxylation reactions essential for the formation of collagen.<\/p>\n

Humans are one of the few mammals that can\u2019t produce vitamin C, because they lack the enzyme L-gluconolactone oxidase, which converts glucose to ascorbic acid. Vitamin C is normally found at high levels in the dermis and epidermis. A study of vitamin C in young, aged and photo-damaged human skin demonstrated that vitamin C levels were 31 percent lower in the epidermis of photo-damaged skin and 39 percent lower in aged skin. In the dermis, vitamin C levels were 37 percent lower in photo-damaged skin and 30 percent lower in aged skin. Environmental pollutants, such as ozone, can also decrease vitamin C levels in the skin and lead to free-radical damage. Additionally, smoking can lead to increased wrinkling and decreased collagen synthesis, which corresponds to a decline in plasma vitamin C levels.<\/p>\n

Ascorbic acid was the second generation of skin-care actives launched in the 1980s following the success of alpha-hydroxyl-acid-based products (AHA<\/a>). However, due to vitamin C\u2019s poor water stability, cosmetic formulations were limited to anhydrous solutions and emulsions. Under aerobic conditions it can reversibly oxidize to dehydroascorbic acid (DHA<\/a>), which can be irreversibly degraded to oxalic acid<\/a>.<\/p>\n

The use of vitamin C (3 to10 percent) in topical applications for at least 12 weeks has been shown to decrease wrinkling, reduce protein fiber damage, decrease apparent roughness of skin and increase production of collagen. Topical vitamin C has also been shown to reverse some of the age-related changes in the epidermis. However, topical vitamin C doesn\u2019t appear to work for all individuals. One study demonstrated that individuals with high dietary intakes of vitamin C showed no or little topical effect.<\/p>\n

Other studies have shown that a formulation containing 10 percent ascorbic acid (water-soluble) and 7 percent tetrahexyldecyl ascorbate<\/a> (lipid-soluble) in an anhydrous polysilicone gel base clinically improved skin wrinkling when used topically for 12 weeks. A topically applied 5 percent vitamin C lotion was also shown to be highly effective at repairing aged skin, inducing significant collagen synthesis in all age groups with minimal side effects.<\/p>\n

Claimed skin benefits for vitamin C and its derivatives:<\/b><\/p>\n